Adding a pre commit check for npm libraries

Extras/Scripts/pre-commit-checks.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+LINT_CHECK_PATHS=(
+    "Common/"
+    "Signalling/"
+    "Frontend/library/"
+    "Frontend/ui-library/"
+    "SignallingWebServer/"
+)
+
+FAILURE=0
+FAILED_PATHS=()
+
+for CHECK_PATH in "${LINT_CHECK_PATHS[@]}"; do
+    STAGED_FILES=$(git diff --name-only --cached "$CHECK_PATH")
+
+    # check if any of the npm packages have changes
+    if [[ -n "$STAGED_FILES" ]]; then
+        echo ${CHECK_PATH} has changes. Running lint...
+        pushd $CHECK_PATH >/dev/null
+        if ! npm run lint; then
+            FAILURE=1
+            FAILED_PATHS+=("$CHECK_PATH")
+        fi
+        popd >/dev/null
+    fi
+done
+
+if [[ $FAILURE -eq 1 ]]; then
+    echo Linting failures in the following paths...
+    for FAILED_PATH in "${FAILED_PATHS[@]}"; do
+        echo "    $FAILED_PATH"
+    done
+    exit 1
+fi
+
+